Fermentable non-digestible carbohydrates and fiber from plant food sources are suggested to prevent high fat (HF) diet-induced gut microbial dysbiosis and other obesity-related outcomes. Various parts of mango have been studied for their anti-obesogenic, immunomodulatory and gastro-protective properties. This study investigated the effects of 12-week freeze-dried mango pulp supplementation on the gut microbiota and their fermentation products, and its impact on body composition, glucose homeostasis and gut inflammatory markers in C57BL/6 mice fed a HF diet. Six-week old male C57BL/6 mice were randomly assigned to four dietary treatment groups: Control (AIN-93M, 10% kcal from fat), HF (60% kcal from fat), and HF+1% or 10% mango. Cecal content analyses using 16S rDNA sequencing showed that HF feeding reduced Bifidobacteria and Akkermansia while mango supplementation prevented the loss of these populations in a dose-dependent manner. In contrast to previous studies, mango supplementation did not reduce body weight or fasting blood glucose. Interestingly, both mango doses lowered HF-induced hypertriglyceridemia. The HF+10% mango significantly lowered plasma non-esterified fatty acids, but increased plasma total cholesterol. In comparison to the HF group, a dose-dependent increase in microbial fermentation was observed with mango supplementation, as evident in increased fecal and cecal acetic and butyric acid, but not propionic acid. Furthermore, mango supplementation modulated gut inflammation, as observed with an increase in ileal and colonic interleukin (IL)-10 gene expression compared to the HF group. These findings demonstrated that mango supplementation in high fat feeding modulated some of the adverse effects that accompanies high fat diet-induced obesity.